This page will show you how to force your Telstra/Bigpond Sierra Wireless 320U or 760S to lock on to Telstra 4G LTE 1800MHz. Locking on will allow your modem to ignore all other available networks, which is exceptionally handy in low signal areas or where a nearby 3G or Next-G tower is overpowering the available 4G.
You won't need any special tools or skills, just the software that comes with your modem and a dash of common sense.
Open the Bigpond connection manager.
Now hold the Shift key and click Options (hold Shift + click Options)
There will now be a new tab revealed named Diagnosis.
This tab displays all sorts of handy options but the one we're interested in is the Modem Terminal button.
Click the Modem Terminal button.
Once the new screen has popped up, type AT!BAND=03 into the text box at the bottom and press send.
This command sets the operating band to operate on LTE 1800MHz only, and ignore everything else.
This process can be undone by typing the command AT!BAND=00 which switches the modem back to searching on all bands (it's default setting).
Enabling SMS on the Telstra 4G 320U USB Modem
Just another handy little tip, to enable SMS on the Telstra 4G modem we can repeat the above process but sending the following two commands instead:
Then unplug the modem from your computer and reinsert. You will now notice the messages icon will be enabled.
Thanks to JRZ on Whirlpool for suggesting this tip! (Ref: http://whrl.pl/RdcWtb)
For remote operation, programming, or any other situation, the modem can also be operated over a COM port by using a program such as HyperTerminal, or the RS232.h header file when programming. You can locate the COM port via the device manager and scrolling down to Ports (COM & LPT), and looking for Sierra Wireless AT Command Interface.
Note that you'll need to send AT+CFUN=1 to turn on the radio before sending further instructions.